1. Field of the Invention
The present invention relates to a rolling guide unit that guides an object to be moved along a curvature, and which is equipped on, for example, a machine tool or industrial robot.
2. Description of the Prior Art
An example of this type of rolling guide unit of the prior art is shown in FIG. 1. Furthermore, although said rolling guide unit is disclosed in Japanese Patent Laid-Open Publication No. 63-186028, a similar construction is also disclosed in Japanese Patent Laid-Open Publication No. 62-101914.
As shown in FIG. 1, this rolling guide unit is equipped with track rail 1, in which one track each in the form of track groove 1a is formed on both the right and left sides along the lengthwise direction, slider 2 able to move relative to said track rail 1, and a plurality of rolling elements in the form of balls (not shown) arranged and contained within a rolling element circulating path (not shown) formed in said slider 2 that bear the load between track rail 1 and slider 2 by circulating while rolling over said track grooves 1a.
As shown in the drawing, track rail 1 has a constant curvature in the lengthwise direction, and slider 2 moves along this curvature. Furthermore, as is clear from the drawing, the cross-section of track rail 1 is of a roughly rectangular shape, while the cross-section of slider 2 is roughly U-shaped, with said slider 2 straddling this track rail 1.
The present invention provides a rolling guide unit having a construction as is described below that is basically different from the above-mentioned rolling guide unit of the prior art, the details of which are described later.
Namely, track rail 1 is equipped with a flat bottom and a pair of side walls in which tracks are formed in the inside surfaces that extend roughly perpendicular to said bottom from the right and left sides of said bottom, and has a cross-section roughly in the shape of the letter "U". A slider is inserted in said track rail so as to be sandwiched between both said side walls.
In the case of the rolling guide unit having said construction, since the tracks of the track rail are provided on the inside surfaces of the above-mentioned side walls, finishing processing in the form of grinding of said tracks cannot always be performed easily.